It's Showtime for West Winger, Princess Leia

The West Wing's Donna ain't lovelorn no more. Janel Moloney is joining the cast of Showtime's Brotherhood for at least four episodes this season, playing a woman who has an affair with Jason Clarke's ambitious politico. (All together now: Poor Annabeth Gish.)In other Showtime news, in addition to Matthew Modine joining Weeds for at least 10 episodes (first scooped by the Ausiello Report, he'll serve as a love interest for both Nancy and Celia), Zooey Deschanel's krazy Kat is returning for the Season 3 opener, while Carrie Fisher will guest this season as Celia's "May-the-divorce-be-with-you" lawyer.